Wireless receiving system



Jan. 12 1926.

Q. A. BRACKETT wnumss RECEIVING SYSTEM INVENTOR 'Qumcyl. Bracket! FiledAugust 5 1919 WITNESSES:

ATTORNEY Patented Jan. 12, 1926.

UNITED STATES PATENT OFFICE.

QUINCY A. BRACKETT, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTING-HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

WIRELESS RECEIVING SYSTEM.

Application filed August 5,3919. Serial No. 315,893.

To all whom it may concern:

Be it known that I, QUINCY A. BRACK- n'rr, a citizen of the UnitedStates, and a resident of Pittsburgh, in the county of Allegheny andState of Pennsylvania, have invented a new and useful Improvement inWireless Receiving Systems, of which the following is a specification.

My invention relates to wireless receiving apparatus and it has for itsobject to prom e apparatus of the character designated that shall besimple and rugged in construction and highly effective in operation toproduce clear and distinct signals in the local circuit, even althoughthe incoming impulses may be relatively weak in character.

In the accompanying drawing, Fig. 1 is a diagrammatic view of a Wirelessreceiving circuit embodying one form .of my invention; and Figs. 2 and 3are similar views of modifications of the circuit shown in Fig. 1.

In the recei t of wireless signals, the energy derived rom the antennais generally insuflicient in amount to produce clear and audible signalsif used directly. It is usual, therefore, to employ an amplifyingdevice, this frequently taking the form of an evac: uated tube providedwith an electron source, such as a hot cathode and with a cold anode,these two electrodes being placed in the local receiving circuit andseparated by a grid electrode connected to the antenna. The number ofelectrons flowing between the hot cathode and the cold anode and,consequently, the current flowing in the local circuit, is determined bythe grid potential, and thus a current impulse derived from the antennacircuit may be amplified or multiplied many-fold for application to thelocal receiving circuit.

In accordance with the present invention, I attain the same generalresult as above outlined but I cause the antenna circuit to control anelectron stream which intercepts o1 interacts with the electron streamrelated to the local receiving circuit. Variations in the number ofelectrons flowing in the antenna electron stream vary the number ofcolfects or other interactions with a consequent disturbing effect uponthe electron stream relating to the local receiving circuit. Thus,current variations may be multiplied manyfold in order to secure clear,shar and distinct signals, with relatively wea antenna .energiz ation.

Referring to the drawing for a more detailed understanding of myinvention, I show a receiving antenna at 5 in Fig. 1, the antenna beingconnected to ground through the primary winding 6 of a couplingtransformer 7 having a secondary winding 8. The secondary winding 8 isconnected to the anodes 9+9 of an evacuated receiving bulb 10 that isfurther provided with a hot cathode 11, preferably disposeddiametrically opposite the anodes 99. The cathode 11 is energized, as bya suitable battery 12, and is connected to substantially the mid-pointofthe secondary winding 8.

The elements thus described serve to rectify any alternatingelectromotive force generated in the winding 8 and to produce aunidirectional electron flow from the cathode 11 to the anodes 9-9, allas set forth and claimed in detail in my eopendingapplication, SerialNo. 442,381, filed Feb. 4, 1921.

The tube 10 is further provided with a hot cathode 13 disposed oppositea plate anode 14, these two electrodes being included in a localreceiving circuit embodying a receiver 15 and a current source 16,shown, in this case, as a battery. The electrodes 13 and 14 are sodisposed that an electron stream therebetween is intercepted by theelectron stream between the electrodes 99 and the cathode 11.

Having thus described the arrangement of apparatus embodying myinvention, the operation thereof will be as follows: Upon closing thereceiving circuit and heating the cathode 13, as by a battery 17, anelectron stream flows from the cathode 13 to the anode 14, producingcurrent flow in the opposite direction through the local receivingcircuit. Upon the receipt of signals on the antenna 5, alternatingcurrent is produced in the secondary winding 8 and is rectified by theanodes 9-9 and the cathode 11, producing electron flow from the cathode11 to the anodes 99, this electron stream intercepting or otherwiseinteracting with that existing between the electrodes 13 and 14. Thecollisions of the electrons, or interactions resulting from static-fieldor other effects of the electrons, in what may be called the antennaelectron stream, with the electrons in the local-circuit electron streamcauses the latter to be diverted from its true path so that theelectrons thereof do not impact upon the anode 14, producing currentvariations in the local receiving circuit. By proper design, thesecurrent variations may be caused to greatly exceed the currentvariations in the antenna circuit itself, thus producing loud andclearly distinct signals in the receiving device 15.

Referring to the form of my invention shown in Fig. 2, an antenna 5receives the signals, as before, but may be closely coupled to the localreceiving circuit, as through an auto-transformer 20. The receiver bulbembodies the same number of electrodes as before but they aredifferently arranged, as follows: The hot cathode 11 ertaining to theantemia circuit is disposed opposite the antenna anodes 9-9 but isspaced sufliciently away from the opposite wall to permit thepositioning of the plate anode 14 therebehind. The hot cathode 13,pertaining to the local receiving circuit, is disposed between the hotcathode 11 and the anodes 9-9. Thus, in operation, the electron streampertaining to the antenna circuit may be indicated by an arrow 21, andthe electron stream pertaining to the local circuit by an arrow 22,pointing in the opposite direction. The local receiving circuit is shownas being energized as in the system of Fig. .1.

Having thus described the arrangement of the system of Fig. 2, the.operation is as follows: Upon establishing {connection to the source 16,an electron stream flows from the cathode 13 to the anode 14, asindicated by the arrow 22. The resultant current flow is uniform and soproduces no noise in the receiver 15, after the initial click. Thereceipt of signals produces spaced electron discharge or spurts from thecathode 11 to the anodes 9 and 9 as indicated by the arrow 1,. in the.opposite direction from that indicated by the arrow 22. Thus thereceipt of a signal causes serious interference or other reaction withthe electron flow in the local circuit, with the reproduction of clear,audible signals.

In the form of my invention shown in Fig. 3, the general arrangement ofcircuits is the same as that shown in Fi 2 but a somewhat different typeof amp ifier' tube is employed, in that the flow of electrons in theantenna electron path is such as to assist the flow of electrons in thelocal receiving path, thus increasing the current flow and the loudnessof signals in the receiver upon the receipt of incoming signals, ratherthan by decreasing the electron stream, as in the system of Flg. .2.Thus, the anodes 9-9 are disposed opposite the antenna cathode 11 andthe local circuit cathode 13 is disposed in proximity to the antennacathode 11. The local-circuit plate anode 14 is disposed between therectifying anodes 99. The antenna electron stream may be indicated inposition and direction by an arrow 30, and the electron streampertaining to the electron receiving circuit by a similar arrow 31,substantially coincident with the arrow 30.

Upon closing the local receiving circuit,

- the electron stream 31 is initiated between the electrodes 13 and 14and flows with fixed characteristics until signals are received on theantenna 5. Under these conditions, electron flow from the cathode 11 tothe anodes 99 is indicated by the arrow 30 and the effect of thiselectron stream is to materially increase the number of electrons drivenover from the cathode 13 to the anode 14. Thus, an incoming im pulse onthe antenna results in marked increase of the current in the localreceiving circuit, thus producing a clear signal as desired for goodtransmission.

Still other changes will be obvious to those skilled in the art, such,for example, as the use of various types ofcoupling and the use of twoor more amplifier tubes to still further increase the intensity of thesignals.

While I have shown and described my invention in its preferred forms, itwill be obvious to those skilled in the art that it is not so limitedbut is susceptible of various chan es and modifications withoutdeparting from the spirit thereof, and I desire, therefore, that onlysuch limitations shall be placed thereupon as are imposed by the priorart or are specifically set forth in the appended claim.

I claim as my invention:

In a wireless receiving circuit, the combination with an antenna havin acoupled transformer associated therewlth, of an evacuated bulb providedwith anodes and an electron emitting cathode, said anodes beingconnected, respectively, to terminal points of the secondary winding ofsaid transformer, and said cathode being connected to an intermediatepoint therein, whereby said electrodes tend to rectify an electromotiveforce produced in said winding and, consequently, to produceunidirectional electron flow from said cathode to said anodes, anadditional electronemitting electrode and a cold anode also mountedwithin said container and so disosed that an electronpath therebetweenmtercepts the aforementioned electron stream, and an electricalreceiving circuit connecting said last-named electrodes and embodying asource of electromotive forces and a receivingdevice, whereby anelectromotive force supplied through said coupled 7 5 transformer tosaid anodes produces interlocal receiving circuit because ofmodifications of the number of electrons traversing the same.

In testimony whereof, I have hereunto subscribed my name this 30th dayof July,

QUINCY A. BRACKETT.

